The relative ease with which vertical cavity surface-emitting lasers (VCSELs) can be fabricated has resulted in the increasing use of VCSELs in a variety of applications such as printing, data storage and network communications. However, the small light emission area of each VCSEL severely limits the light output power that can be generated and output by each VCSEL. This shortcoming is especially severe in single mode devices. The narrow beam profile of single mode devices is highly desirable in a range of applications ranging from printing to wide area network communications.
One method of increasing the optic power at a target point is to align and simultaneously switch several lasers to form a composite beam. However, using an array of independent lasers results in each laser having its own independent intensity pattern. Combining independent intensity patterns results in a composite beam that appears as several distinct spots. These distinct spots are unsuitable for communications and printing applications where a central radiation lobe with a high concentration of power output is desired.
Thus an improved method of combining the output of an array of lasers, preferably VCSELs, to generate a single spot composite beam is needed.